Shortcut methods for nonideal multicomponent distillation: I. Simple columns

TLDR

Shortcut methods are essential for quickly evaluating alternatives in process design. The paper presents the rectification body method (RBM) for calculating the minimum energy demand of homogeneous, azeotropic multicomponent distillation processes. RBM generalizes the Underwood technique by incorporating all pinch point branches of both column sections, eliminating the need for a priori active pinch point selection, and is applicable to any split of nonideal and azeotropic mixtures regardless of component number, as illustrated with three‑, four‑, and five‑component examples. RBM significantly extends previous results and enhances practical applicability.

Abstract

Abstract Shortcut methods are a prerequisite for the fast evaluation of alternatives in process design. The rectification body method (RBM) for calculating the minimum energy demand of homogeneous, azeotropic multicomponent distillation processes is presented. The new method incorporates both the classical Underwood technique and certain previously proposed techniques as special cases. It employs all pinch point branches of both column sections and thus requires no a priori selection of active pinch points. It is entirely general and can be applied to any type of split of nonideal and azeotropic mixtures irrespective of the number of components. Hence, it significantly extends previous results and practical applicability. Its features are highlighted through examples of nonideal separations with three, four, and five components.